On Tuesday, July 10, 2018 at 8:24:38 PM UTC-6, Brent wrote: > > > > On 7/10/2018 6:50 PM, [email protected] <javascript:> wrote: > > > > On Tuesday, July 10, 2018 at 4:42:44 PM UTC-6, Brent wrote: >> >> >> >> On 7/10/2018 3:01 PM, [email protected] wrote: >> >> *IIRC, the above quote is also in the Wiki article. It's not a coherent >> argument; not even an argument but an ASSERTION. Let's raise the level of >> discourse. It says we always get a or b, no intermediate result when the >> system is in a superposition of states A and B.. Nothing new here. Key >> question: why does this imply the system is in states A and B >> SIMULTANEOUSLY before the measurement? AG * >> >> >> Because, in theory and in some cases in practice, there is a direct >> measurement of the superposition state, call it C, such that you can >> directly measure C and always get c, >> > > > *Is c an eigenvalue of some operator? How can you always get c, if C is > not an eigenstate of some operator? And if it is an eigenstate, why do you > assert it is a superposition? AG * > > > You just don't get it. c is the eigenvalue of C. C is an eigenstate. >
*Don't underestimate. Yes, if one gets c, c must be an eigenvalue of operator C. AG* BUT it's also a superposition of A and B. It's a simple fact of vector > spaces that a vector can be the sum of other vectors. The only thing > tricky about QM is that it's in a complex vector space so the vectors get > scaled by complex instead of real numbers. And they are *simulataneously > *the sum of other vectors. > *The complex scalar field is not a problem; not even tricky. But a superposition does not necessarily mean the system is physically in both component states simultaneously, even if someone writes the state as a sum. That's what's assumed, without proof. Maybe I missed your proof or argument. AG* > > Brent > > > >> but when you have measured and confirmed the system is in state c and >> then you measure A/B you get a or b at random. The easiest example is SG >> measurements of sliver atom spin orientation where spin UP can be measured >> left/right and get a LEFT or a RIGHT at random, but it can be measured >> up/down and you always get UP. Any particular orientation can be >> *written* as a superposition of two orthogonal states. >> > > *I'm not clear what a left/right measurement is, and how it might be > measured. I assume you mean the directions perpendicular to Up / Dn. In > any event, how is this related to the simultaneity of Up / Dn? AG* > >> >> This is true in general. Any state can be written as a superposition of >> states in some other basis. But it is not generally true that we can >> prepare or directly measure a system in any given state. So those states >> we can't directly access, we tend to think of them as existing only as >> superpositions of states we can prepare. >> > > *I'm OK with superpositions, only their interpretation of simultaneity of > component states. We can measure Up or Dn, and represent the situation > before measurement as a superposition and calculate probabilities, but the > assumption of simultaneity seems unsupported and produces apparent > paradoxes. AG * > >> >> Brent >> > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
